Is there really a need for Canon to develop or redesign lenses that are faster than f/4? Given the surge to digital, such a dev track may not make much economic sense. Sensor technology is only going to get better. Noise at higher 'ISO' (I'd prefer if this vestige from film were tossed and replaced with something like 'gain' which is more accurate) levels is gradually improving. Therefore, the differences in shooting at ISO 100 or ISO 400 are relatively minor and easily compensated for in software if needed. It may be that lenses that are faster than f/4 will be called 'film lenses' in the near future because they really aren't needed in the digital marketplace except as niche items as opposed to mainstream.

Is there really a need for Canon to develop or redesign lenses that are faster than f/4? Given the surge to digital, such a dev track may not make much economic sense. Sensor technology is only going to get better. Noise at higher 'ISO' (I'd prefer if this vestige from film were tossed and replaced with something like 'gain' which is more accurate) levels is gradually improving. Therefore, the differences in shooting at ISO 100 or ISO 400 are relatively minor and easily compensated for in software if needed. It may be that lenses that are faster than f/4 will be called 'film lenses' in the near future because they really aren't needed in the digital marketplace except as niche items as opposed to mainstream.[a href=\"index.php?act=findpost&pid=54217\"][{POST_SNAPBACK}][/a]

One good reason for a faster lens is to get a brighter image in the viewfinder. Especially since many modern digital SLR's use a cheap penta-mirror rather than a penta-prism. An APS sensor means a dimmer image too. Personally I am happy with F4.

The only SLR's I know of with penta-mirror VFs are cheap models, and the best way to improve VF performance would be to upgrade to a better camera, not to use heavy, expensive f/2.8 or faster lenses with such low-end camera bodies.

I agree that a dominant reason for lenses faster than f/4 is VF brightness but my guess is that current fast lenses handle such needs, so that new ones are not needed enough to justify the R&D expense.

As Michael's wish-list for the "next EOS-1 digital body" suggests, what is needed in lenses for the digital era is sharper, not faster, and if anything, it is a bit easier to design an optically excellent lens by staying away from large apertures. Many sources suggest that f/4 is about the limit beyond which optical aberrations become an important limitation on image quality.